1. Field of the Invention
The invention relates to systems and processes of production of three-dimensional products from wire, rods, rebar, or other suitable similar or elongate material of any cross-section capable of undergoing plastic deformation. The three-dimensional products may find use in a broad variety of applications and cover a very large spectrum of shapes.
2. Description of Related Art
Prior U.S. Pat. No. 5,170,654 dated Dec. 15, 1992 disclosed an automatic bending machine permitting the production of some three-dimensional products from wire. With reference to FIG. 1 of this prior patent, a bending mechanism 6 bends the wire in a plane, and a cutter 7 is used for cutting the formed product from the wire. Furthermore, a fixed gripper 8 and a rotating gripper 9 comprise a gripper arrangement functioning to hold the material with fixed gripper 8 and simultaneously rotate the material about its longitudinal axis X with the rotating gripper 9. This is explained at columns 3-5 of U.S. Pat. No. 5,170,654, the entire contents of which are hereby incorporated herein by reference.
A radically different solution to the problem of producing three-dimensional products from wire, tubing, or other elongate material was given in U.S. Pat. No. 4,799,373 dated Jan. 24, 1989 to Benton. With regard to FIG. 1 of this prior patent, a bending mechanism 20 may bend the wire in one plane and may rotate in its entirety about the longitudinal axis of the material 24, in both directions as indicated in FIG. 1 thereof, and as explained at column 4, lines 40-54 of this prior patent. A cutter 76 is included. As explained at column 1, lines 34-36, this machine permits the production of some three-dimensional products from wire, tubing, or other elongate material.
Thus, it may be understood that previously, three-dimensional products were produced in the following ways:
(a) With reference to FIG. 3 of the appended drawings, the products were produced with the aid of automatic machines which include an arrangement of advancement mechanism 3, system for straightening 4, system for measuring of advanced length 17, a bending mechanism 5 that is fixed and bends the wire 1 in one plane thereby generating only planar forms, and which automatic machines include a mechanism 7, that is found between the straightener 4 and the bending mechanism 5 and that holds the material with suitable grippers and simultaneously with other grippers twists it around its longitudinal axis X. A system for cutting 6 of the wire 1 may typically be included.
(b) With reference to FIG. 4 of the appended drawings, the products were produced with the aid of automatic machines which include an arrangement of advancement mechanism 3, straightener 4, a system for measuring of advanced length 17, and a bending mechanism 10 that may bend the wire 1 in one plane and afterwards may rotate in its entirety around the longitudinal axis X of the wire 1 and effect bending again in another plane. Furthermore, a system 6 for cutting the wire 1 may typically be included.
In the first process (a) referred to above, and in automatic machines of this first type, for the generation of the third dimension the material is twisted around its own longitudinal axis X, so that the already-produced portion of the shape comes to the suitable desired angle in relation to the bending tools. There follows the bending to generate the new plane in the product. This way is advisable for the generation of small sides because of the speed that characterizes it. However, for the generation of large sides, such a twisting of the material has the disadvantage that it must occur quite slowly, because the large moment of inertia of the material of the already-produced portion of the shape tends to induce vibrations in, or to deform the already produced angles and sides.
In marked contrast, in the second process (b) referred to above, and in automatic machines of the second type, for the generation of the third dimension in the product, the entire bending mechanism 10 is rotated around the longitudinal axis X of the wire 1 so that the bending tools arrive at a suitable location for there to occur afterwards the bending of the material at the desired angle. This manner of controlled generation of bends in different selected planes within a single product form is advisable when it is necessary to generate large product sides, because it is not necessary, as in the first process (a) referred to above, to turn in its entirety the already produced shape by twisting it at suitable angle about the material's longitudinal axis X.
A great disadvantage in each of the above-described state-of-the-art processes and in machines of the first and second types is that each one of them respectively provides only one respective way for generating the third dimension in a shape. This entails great limitations primarily as to productivity, taking into consideration that the in-question products typically must be produced in very large numbers. It may be readily understood that with shapes that have both large and small sides, whichever process is employed has the consequence of significant delay in production. That is because with the first process, and automatic machines of the first type (a), the delay will occur during the generation of the large sides; while in the second process and automatic machines of the second type (b) the delay will occur during the generation of the small sides of the product space as the entire bending mechanism is rotated.